The present invention is directed to a method and apparatus for the mass production of T-tube fittings, particularly T-tube fittings formed from relatively small diameter metal tubing. These fittings are required in relatively large numbers by the automotive industry to couple flexible hose lines employed in vacuum actuated control systems, windshield washer systems, etc.
While the method and apparatus of the present invention are capable of forming T-tube fittings from tubing of any reasonable diameter, where the fitting is formed from tubing of relatively small diameter, for example, approximately one-eighth of an inch outside diameter, certain problems peculiar to the small size of the tubing arise. Because of the relatively small diameters involved, the margin for error is reduced. The employment of specialized tooling insertable into the interior of the tubes (see Holden U.S. Pat. No. 3,451,113, for example) or the deformation or forming of portions of the tubing into specialized shapes (see U.S. Pat. Nos. Hickman et al 4,253,224, Taylor 1,892,712 or Coe 2,149,508, for example) is greatly restricted, both by the physical dimensions of the tubing and the fact that in the smaller diameter tubing, the ratio of wall thickness to outer diameter is substantially greater than for tubing of larger diameter.
The present invention is especially directed to a method and apparatus for forming T-tube fittings from relatively small diameter tubing at relatively high production rates.